1. Field of the Invention
The present invention relates to a protein food, particularly isolated soybean protein food and concentrated soybean protein food, to which a proanthocyanidin, such as an extract from seeds or skin of grapes, has been added.
2. Description of Related Art
As a representative example of protein foods, there is a nutrient subsidiary food called protein, which forms a market for athletes, females, elderly people, and the like, and the commercial form thereof varies. The raw materials therefor mainly are vegetable protein represented by soybean protein and animal protein, such as albumen and whey.
It is considered conventionally that such protein is used for increasing muscular strength of sportsmen and for diet for females, but recently it is purchased by elderly people and the like, thereby diversifying the user, and as a result it is varied with respect to the flavor and the form, that is, for example, it is flavored with vanilla or cocoa and is in a powder form, a liquid form, a paste form, or a solid form.
Such protein has no problem with respect to nutritive value, but is still required to be improved in flavor and richness in taste. Particularly, in the case wherein the raw material is isolated soybean protein or concentrated soybean protein, the protein is apt to fall short of richness in taste and mild after-taste.
Further, it is known that proanthocyanidins have various physiological activities, such as active-oxygen elimination activity and anticholesterol activity.